Mutual funds and exchange-traded funds benchmarked to the Bloomberg Barclays Aggregate U.S. Bond Index lost about $17.7 billion in value last week, according to a MarketWatch analysis of data provided by Morningstar.

As of a week ago Friday, the roughly 1,700 exchange-traded and mutual funds benchmarked to the index collectively managed about $1.2 trillion. By the close of trading on Thursday, the Bloomberg index registered a total return of minus 1.487 percentage points. Funds benchmarked to an index are supposed to reflect its holdings as accurately as possible, but occasionally there are slight discrepancies.

Because many mutual funds report their holdings only once a month, the total AUM figure used as the basis for these calculations doesn’t reflect changes in valuation due to market movements between Oct. 31 and Nov. 4. It also doesn’t reflect changes due to investor withdrawals between Oct. 31 and Thursday.

The index, which is weighted by market capitalization, comprises a broad range of U.S. dollar-denominated bonds, including Treasurys, asset-backed securities and corporate debt. Only fully taxable bond issues are eligible, which excludes most municipal bonds and inflation-linked government bonds.

Republican President-elect Donald Trump’s unexpected victory over Democrat Hillary Clinton in Tuesday’s election triggered an explosive bond-market selloff—the biggest since the “taper tantrum,” which occurred in the summer of 2013.

Former Federal Reserve Chairman Ben Bernanke unwittingly sparked the taper tantrum when he told Congress that the Fed would “gradually reduce the flow of [bond] purchases” as the U.S. economic outlook improves. The comment led to a prolonged selloff that saw the 10-year yield rise from about 1.6% to nearly 3% between late May and early September 2013.

Many, including a team of macro strategists at Bank of America Merrill Lynch led by David Woo, expect bonds to continue falling as Trump and the Republican-controlled Congress cut taxes and fund infrastructure projects. That will increase the budget deficit and increase the supply of Treasurys as government borrowing rises.

Treasury yields have risen steadily in recent months, after plunging to historic lows following the U.K.’s late-June vote to leave the European Union. Treasurys represent a plurality of the index’s holdings.

Intraday Data provided by SIX Financial Information and subject to terms of use.
Historical and current end-of-day data provided by SIX Financial Information. Intraday data
delayed per exchange requirements. S&P/Dow Jones Indices (SM) from Dow Jones & Company, Inc.
All quotes are in local exchange time. Real time last sale data provided by NASDAQ. More
information on NASDAQ traded symbols and their current financial status. Intraday
data delayed 15 minutes for Nasdaq, and 20 minutes for other exchanges. S&P/Dow Jones Indices (SM)
from Dow Jones & Company, Inc. SEHK intraday data is provided by SIX Financial Information and is
at least 60-minutes delayed. All quotes are in local exchange time.